the numbers are another sign that the big apple is the, quote, safest big city in america. >>> to a cnn exclusive now. new information on south african leader nelson mandela coming from his own granddaughters. they contacted and spoke exclusively to nadya bilchik. >> over the last few weeks, the entire world has been monitoring the treatment of your grandfather nelson mandela. and he was released from hospital on wednesday. i know the two of you saw him this week. how would you describe his condition? >> we were just so happy that our grandfather's home after his hospital stay. he's doing extremely well. he's surrounded by family. we saw him this afternoon with the kids. and he was happy to see the kids. he's really, really been taken care of very, very well. and we'd like to thank the whole world for sending us messages and keeping us in your prayers. we're just so happy and happy he's home. he's doing extremely well. >> and you said he was playing with the kids? so he's actually sitting up? is he walking? >> he's sitting up and he was waving at the kids and he was smiling at the kids.